Replacing spedo gear in Toploader

c_forshaw · #1 (**permalink**) 10-05-2002, 07:52 PM

I need to replace the speedo gear in a Toploader. I only see one set screw holding in the cable and gear. The gear will not come out. I jacked up the rearend and moved the wheels, but still would not come out. Should I move the rear wheels with the trans in gear? Any other suggestions?

Cal Metal · #2 (**permalink**) 10-05-2002, 09:40 PM

Are you talking about the housing that holds the gear???

poorboy · #3 (**permalink**) 10-05-2002, 09:52 PM

Take a pair of pliers or vise grips and get ahold of the cable at the very end of it, turn the cable back-n-forth while pulling out on the pliers. The end of the cable in the housing has an o-ring on it and they will stick.

Poorboy

c_forshaw · #4 (**permalink**) 10-06-2002, 04:10 PM

Thanks, that did the trick.

Wayne Maybury · #5 (**permalink**) 10-07-2002, 08:01 AM

One thing I learned (the hard way) is that there are LH and RH speedo gears for toploaders. Make sure which you require.

Wayne

excelguru · #6 (**permalink**) 10-07-2002, 08:40 AM

Speaking of speedo gears... I have a close-ratio toploader mated to a 3.31 Jag rear and was told that the 19-tooth speedo gear was closest to what I needed. (Apparently, there is no speedo gear made with exactly the number of teeth I need.) So this is what I use.

Because of the tooth-count discrepency, the speedometer reads much lower than actual speed (sometimes as much as 15 to 20 MPH lower from what I can tell). Do any of you guys know of a tooth count that would at least get the indicated speed closer to the actual speed? Does anyone else have this delimma?

Also, should I have slathered the gear with white lithium grease or something similar when I installed it? I didn't use any lube because I figured the gear would get plenty from the transmission itself.

Keith

Bob Putnam · #7 (**permalink**) 10-07-2002, 09:27 AM

XL,

My recommendations for gears (it wouldn't have been a 19T) are here.

You also may have a 6 tooth driving gear rather than the more common 7 tooth gear. I would use a timed measured mile or a GPS to determine your exact speed and the deviation from the speedo reading - then figuring the proper gear from that.

renaissance man · #8 (**permalink**) 10-07-2002, 12:10 PM

I'm using a 20 tooth gear in my wide-ratio Toploader with a 4.10 rearend. I'm reading 60 mph when it's actually 62. That's about as close as I'll get, I'm sure.

Ron61 · #9 (**permalink**) 10-07-2002, 01:03 PM

This is more of a question than an answer. Bob, I have a letter that I received from one of the car magazines a year or so ago dealing with Ford speedometer gears and they told me that each tooth is worth approximately 4 MPH in speed. We addded two teeth to a friend of mines car which by the radar was reading 10 miles an hour fast and it now reads about 2 miles per hour fast. Is this a fact or did we just happen to get lucky ? I did print out the sheet that you put in your post and will use it for reference from now on.

Thanks,

c_forshaw · #10 (**permalink**) 10-07-2002, 02:28 PM

When I purchased a new speedo gear today, the parts rep at Ford told me each tooth was worth about 4 mph.

Mr.Fixit · #11 (**permalink**) 10-07-2002, 03:42 PM

Blanket statements like that make math seem useless. Count the teeth on the gear in the tranny, count the teeth on the speedo cable's gear. From here it's just fractions and ratios to determine how many teeth you will need on the gear, round to the nearest whole integer.

c_forshaw · #12 (**permalink**) 10-13-2002, 07:18 AM

I changed from an 18 teeth speedo gear to 19 and it made about 4 mph difference (per GPS).

Tom Kirkham · #13 (**permalink**) 10-13-2002, 09:46 AM

Another option instead of using a reversing gear (I hate them, they brake speedo cables and make the speedo bounce) is to use the speedo gears out of a Galaxie toploader (they are the same as the 3 speed and C4). To help figure out the speedo gears you need, it takes 1000 revs to equal one mile on most speedos.